|
|
||||||||
1 Department of Nutrition and Food Sciences, Utah State University, Logan 84322-8700
Monthly milk samples were collected from 19 Holstein and 19 Jersey cows in separate herds during 10-mo lactations (380 total samples). Effects of breed-herd, lactation number, season, and stage of lactation and the interactions of these parameters on plasmin, plasminogen, and milk-clotting measurements were determined. Lactation number had the greatest influence on plasmin activity, which increased during lactation but was not influenced by breed-herd, pH, protein, or fat. Stage of lactation and season were the only factors that influenced plasminogen. Percentage of plasminogen activated was highest during late lactation, in milk from fourth and later lactation cows, and during fall and winter. Plasmin activity did not influence milk-clotting parameters. Clotting time decreased as pH decreased and as protein and fat increased. Increased protein and fat improved firming rate of curd. Milk samples collected in the fall had the highest firming rates, and stage of lactation did not influence firming rate. Lower pH, higher protein, and higher fat decreased cutting time. Increased protein and fat improved curd firmness. Jersey herd milk had firmer curd than Holstein herd milk. Lactation number and stage of lactation did not influence curd firmness.
Key Words: plasmin plasminogen milk coagulation lactation
Submitted on December 26, 1990
Accepted on June 17, 1991
This article has been cited by other articles:
![]() |
R. Dal Zotto, M. De Marchi, A. Cecchinato, M. Penasa, M. Cassandro, P. Carnier, L. Gallo, and G. Bittante Reproducibility and Repeatability of Measures of Milk Coagulation Properties and Predictive Ability of Mid-Infrared Reflectance Spectroscopy J Dairy Sci, October 1, 2008; 91(10): 4103 - 4112. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Frohbieter, B. Ismail, S. S. Nielsen, and K. D. Hayes Effects of Pseudomonas fluorescens M3/6 Bacterial Protease on Plasmin System and Plasminogen Activation J Dairy Sci, October 1, 2005; 88(10): 3392 - 3401. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Bianchi, A. Bolla, E. Budelli, A. Caroli, C. Casoli, M. Pauselli, and E. Duranti Effect of Udder Health Status and Lactation Phase on the Characteristics of Sardinian Ewe Milk J Dairy Sci, August 1, 2004; 87(8): 2401 - 2408. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Albenzio, M. Caroprese, A. Santillo, R. Marino, L. Taibi, and A. Sevi Effects of Somatic Cell Count and Stage of Lactation on the Plasmin Activity and Cheese-Making Properties of Ewe Milk J Dairy Sci, March 1, 2004; 87(3): 533 - 542. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |